Male contraception: Cutting of sperm"s power supply could make a man temporarily infertile

Off with their tails! Male contraceptive pill a step closer as scientists cut off the power supply that helps sperm swim
Gene mutation disrupted their ability to swimResulted in sperm tails that were 17 per cent shorter and a 50 per cent reduction in sperm production



12:05 GMT, 9 October 2012

Scientists have found a way to stop sperm swimming, making the long-awaited male contraceptive pill a step closer to fruition.

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Alternative therapy: A jab to halt sperm production is also being developed

And because the gene is found elsewhere in the body, such as tissues in the brain, liver and kidneys, the pill would need to be programmed to work only on the testes.

The research was done in conjunction with the universities of Cambridge and Newcastle in the UK and published in the journal PLoS Genetics.

Previous research has found that 55 per cent of men would be willing to take a male contraceptive pill.

But a British study published in 2010 found that women didn’t trust men to take a contraceptive pill every day.

Other forms of male contraception being developed include an injection given to men once a month.

The testosterone jab is administered in the buttocks and works by regulating two brain chemicals to block sperm production temporarily.

A two-year trial in China involving 1,000 men found the injections were 95 per cent effective at preventing pregnancy.

But a third of the dropped out of the trial, suggesting they were unwilling to undergo the ordeal of monthly injections and potential side-effects that include mood swings, lower sex drive and acne.

Another option is a pill that prevents sperm from being released on ejaculation.

The pill uses compounds found in blood pressure and anti-psychotic medication used in the Sixties, which were found to have the side-effect of ‘dry ejaculation’.

These paralyse certain muscles in the male reproductive system, causing a temporary block of the release of semen while having no adverse effects on libido, sexual performance or sensation, so the man still has an orgasm, but produces no fluid.

Studies by researchers at King’s College Hospital, London, suggest the pill works within three hours and lasts for two days, so it is taken when required.